No.251 Fuze

[oktato]

Hi,
Sorting through some bits and pieces and thought this could be interesting.
I'm pretty sure it's a No.251 fuze for a 40mm Bofors shell.
The outer ring is stamped 251-III WB3BL.
WB must stand for Wilmot-Breeden Ltd, Birmingham.
Does anyone know if this is WW2 or later?
Thanks,
Gary

 

[Weasel]

Hi Gary,
Thats a really nice set, thanks for showing it.
Best regards Weasel.

 

[Darren]

Very nice Gary!

 

[Darkman]

Very nice item!

Yes, No. 251 fuses are WW2 era only. At the start of WW2 the No. 250 fuse was utilised, and I have these dated up until 8/1940. I then have No. 251 Mk I and Mk III fuses all dated 1941 and a Mk III dated 2/1942. Towards the later part of WW2 the No. 255 was introduced (not sure when - mine are undated or postwar dated, but they were definitel introduced in WW2). So that makes the 251 slap in the middle of WW2. Cheers, Graeme

 

[2pounder]

fuze list gives 250 1938 to 1946, the 251 1939 to 1960, the 255 1943 to 1963 the first date is introduction so one can pressume manufacture started but the second date is obsolete date, I guess that means some around somewhere but could have stopped manufacture much earlier.

 

[oktato]

Thanks for the info, Graeme.
That's exactly what I wanted to know.
Best regards,
Gary

 

[Bonnex]

Fuze 251

A couple of items of information that might be of interest:

Fuze, Percussion, Direct Action, No 251
Design DD/L/8080. Nose percussion, for use with 40mm Bofors AA gun HE shell.

List of Changes entries:-
Mark I B3131 of 14/8/1938 Introduction
Mark IA B5035 of 19/2/1941 Thicker cover plate of brass instead of copper
Mark II B4073of 12/4/1940 New plastic hammer and new needle
Mark III B5035 or 19/2/1941 2 balls supporting the striker instead of three. This paragraph makes the Mk I and Mk II obsolescent (stocks to be used up)
All Marks Obsolete by App. K/1684 of 27/5/1960

 

[Darkman]

Thanks 2pounder and Bonnex. The introduction dates and design mark changes are very interesting. Looks like it took a while for manufacturers to change over production (tooling changes), as I have 2 x No. 250s of presumably British manufacture with "6/40" and "8/40" dates. (We did not have our own manufacture of 40mm shells up und running this early in Australia, so everything was imported and of British or Canadian make at that time.)

The design changes appear to be incomplete as one of the obvious external differences between a No. 251 Mk I and Mk. III fuse is that the hammer cover on the Mk. III is fully enclosed - Mk. I has the copper/brass disc closure for the hammer on the nose cap, but with Mk. III it is fully covered over and integral with the aluminium nose, as per later fuses.

 

[Bonnex]

I was asked about the meaning of App. K/1684.

The App means 'approval' and this represents the authority for any action (e.g. Introduction) with respect to a store. I include the Extract of Approval K/1684 (which is now unclassified) for the demise of the 251 Fuze. The process of 'Approval' "usually requires the collective agreement of several authorities inside and outside the War Office" (to quote an Ordnance document).

The 'List of Changes' which was a monthly pamphlet issued by the War Office from 1860 to 1965 showing new, or changes in pattern, is not the actual authority for a change in status of a store but it usually shows the authority (or approval) in the margin. The date of the issue of a List of Changes is no indication of when a store was 'changed'. Stores were often in service well before they appear as 'Introduced' in Lists of Changes.

Words such as 'Obsolete', 'Obsolescent' and 'Sealed' have specific meanings in approvals-speak. Obsolescent for instance means something close to "we are not going to manufacture any more of these but they are quite safe to use until we tell you otherwise".

Clear as mud I expect but ask if you have any questions.





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